Various vehicles, such as automobiles, aircraft, and maritime vessels, may include power distribution systems for generating and distributing power, often electrical, to various loads included onboard the vehicle. In the case of an aircraft, loads commonly found in the power distribution system include the flight controls, avionics, galley ovens, heaters and refrigeration units, lighting, fans, de-ice and anti-ice, etc. Typically, the power distributed to the loads by these systems is generated via an engine that is utilized both to propel the vehicle and to drive a generator. As such, the power generated by the engine must be allocated between electrical power generation and vehicle propulsion activities (and as such, the engine/propulsion mechanisms can be thought of as another load on the system, although not electrical, further dissipating energy). It is therefore desirable to design electrical power generation and distribution systems so as to distribute power efficiently between the electrical power utilization and the vehicle propulsion.
More recently, aircraft designs have increased the use of electrical power onboard an airplane. For example, recent innovations include an electrical starter-generator, which is used for engine starting and power generation, electrically powered environmental control and pressurization systems, electrical actuation (flight controls), and electrical anti-ice and de-ice systems. With the inclusion of these new loads, total electrical loading onboard an aircraft could be raised from around 100 kilowatt (kW) to around 1 megawatt (MW).
One of the factors contributing to the electrical losses on aircraft is the relatively long distance over which power typically must be transmitted before reaching loads and the concomitant power dissipation. As mentioned earlier, aircraft power generation is typically carried out by generators associated with engines. However, as illustrated in FIG. 1, the engines 18 in many conventional aircraft 1 are positioned on the wings 16, this positioning being dictated by and optimized for propulsion and aerodynamics considerations rather than electrical power distribution considerations. Because of the engine positioning, power generated by the generators 14, typically alternating current (AC) power, must travel the distance from the wings 16 across to the body of the airplane 10 where it is fed into an AC bus 20. This power is then converted to DC power, often by a rectifier 22, and fed to a DC bus 24 from which the power is distributed over the distance of the body 10 to loads 8 distributed therethrough. In all, the power is transmitted significant distances between the point of generation and the point of beneficial use. In so doing, a significant amount of power is dissipated via line losses, and this raises the amount of power that must be initially generated. There is a therefore a need in the art for a power distribution system in which power is used more efficiently and power dissipation through line losses is reduced. Further, transmission of relatively large amounts of power requires larger conductors and network components rated for higher power applications, which can disadvantageously increase weight and cost of the power distribution system. As such, there is a need in the art for a power distribution system that reduces the need for and/or use of high power conductors and components.